Flat panel displays (FPDs) have become popular in recent years, especially in the consumer electronics industry. Currently, active matrix liquid crystal display (AMLCD) is the predominant technology. In addition, Organic Light Emitting Diode (OLED) display technology is experiencing positive growth. In a typical AMLCD, an active thin film transistor (TFT) is used as an electrical switch to control each pixel in the display. There are two main process methods that are currently used for creating integrated peripheral circuits, current driving backplane such as OLED, or switches on a glass substrate that supports the fabrication of TFTs: amorphous silicon (a-Si) and polycrystalline silicon (poly-Si). The a-Si based TFTs are typically physically larger than the poly-Si TFTs because of slower electron movement. In contrast, poly-Si TFTs are smaller and faster, allowing for improved aperture ratios and higher pixel densities.
Although poly-Si process leads to higher display performance than a-Si process, a-Si fabrication process is still popular in display manufacturing facilities. This is due primarily to the relatively lower costs of a-Si that result from fewer process steps and less expensive equipment. It is, therefore, desirable to have a fabrication process that may combine the inherent low cost of a-Si manufacturing and the higher performance poly-Si process.